Make sure you have equipped your gear before you leave the chamber, and also save your game. The next section is where you will fight your first battle. Navigating your way out of the underground passage is pretty straightforward, but you'll need to use some strategy in battle. Also make sure you collect all of the chests on the way, even the ones that are out of the way (see images.)
Sometimes people get discouraged at this point and say the game is too hard. You may die on your way through this section of the game. Here are some tips that make it easier:
At the end of this watery chamber you'll meet up with a curious character named Rider. He will join you in your quest. This makes fighting battles much easier. Leave this area by heading out the door to the next one.
The next area begins in a large underground room with a big pit in the center. Move to the right around the pit and stick on the path to make it to the next chamber. If you're doing well and you're adventurous, there is a secret wall (note the small difference in colour.) You'll have to navigate blindly and at the end you'll be rewarded with some treasure chests.
See slightly discoloured left edge tile, that is the entrance to the secret passage.
So you've made your way through several underground chambers, you must be near the end now, right? Yes! In this room you'll notice there are no random battles but if you move to the pass between the rocks on the East end of the room, you'll find the first boss! Before you do that, use the healing fountain in the same room (see images.)
The first boss is a water monster. He looks scary right? Well he is, but he has a weakness. During Rider's turn, use the Bolt1 spell on him to do maximum damage. You'll have to blast him several times while attacking with Eny. Soon enough he will fade away and you'll have beaten the first boss.
There is a hidden chest just after the boss (see images) as well as some in plain sight. After you fight the boss, use the curing fountain again because you're not out of trouble yet. It is also recommended that you save your game after using the curing fountain. Up the stairs you'll find yourself back in the forest where this whole adventure started. Rider will send his horse away and you must exit the forest, but beware, monsters have been summoned into the land and you'll have some opposition. Which way do you go? Well that depends if you want to tempt death or not. Going North is the easiest, shortest route, and you won't miss much going this way. If you're really masochistic, the Southern route is more scenic.
Some enemies can poison you with their attacks, which will cause you to lose hit points every time you take a turn in battle, and every step you take in field view. Using a Heal potion or spell will cure this ailment. You will notice a purple haze around your character as you walk around if someone in your party is poisoned.
As you found when fighting the water Monster, enemies can be weak to certain spells. In the forest you'll find some of the wooden/flammable enemies are weak against fire attacks. Know when to use your spells to make combat quicker and easier. A Treant will take at least 2 blows from a melee weapon with the weapons and experience you have when you first encounter them, but a single blast of Fire1 will take one down.